Firebox



Aug.. 12, my

L. E. SEELEY FIREBOX Filed Nov. 15, 1938 Patented Aug. 12, 1941 FIREBOX Lauren E. Seeley, New Haven, Conn., assigner to The H. B. Smith Company, Incorporated, Westfield, Mass., a corporation of Massachusetts Application November 15, 1938, Serial No. 240,447

2 Claims.

This invention relates to an improvement in ire boxes, and more particularly in lire boxes for cil burning boilers. Fire boxes and combustion chambers for oil burners are commonly constructed of refractory material or metal of various shapes and sizes, depending upon the size and type of oil burner to be used and the space available in the boiler or boiler setting. The object is to provide a heated chamber in which the oil may be vaporized, mixed with air and burned. In some instances the combustion chamber is built against the water-cooled surface of the boiler itself thus shielding such portions of the boiler in a Way to prevent the large absorption of heat that would otherwise take place. The only heat absorbed is that which may be conducted through the combustion chamber to the boiler surface in contact with said chamber. The heat thus conducted is relatively small.

rihe primary object of this invention is to provide the combustion chamber or re box with a plurality of passages on the back side next to the boiler surface, which passages lead to a hori- Zontal ilue passage beneath the hearth or bottom of the re box, said passage communicating in a suitable manner with the smoke pipe. Thus a means is provided whereby a certain fraction or all of the flue gases may descend through the plurality of passages, giving up heat to the boiler surface that is commonly shielded and inaccessible to the hot flue gases. The result is a more efficient use of the boiler heating surface with higher capacities and eihciencies than otherwise would be possible. This arrangement may also v reduce draft requirements and exert a benecial effect upon oil burners which are inclined to pulsate. The above must be considered as collateral advantages depending upon design of the remainder of the boiler and the tendency of the oil burner to pulsate. The invention is not a specific remedy for pulsation but is helpful in many cases. The impro-ved use of boiler heating surface is definitely achieved by this invention. Where boiler heating surface does not lie behind the iire box, the invention has no application. The plurality of passages may be formed by grooving the walls of the chamber to form continuous passageways, by forming passageways through the walls of the chambers or re box or in the boiler itself or by any other means.

This and other objects-of the invention will appear from a consideration of the following description of the invention and of the drawing which forms a part thereof, and in which Fig. 1 is a longitudinal sectional View of a f boiler provided with a fire box embodying this invention;

Fig. 2 is a cross-sectional view of such nre box;

Fig. 3 is a cross-sectional view of another form of re box embodying this invention; and

Fig. 4 is a fragmentary View in cross section, illustrating still another embodiment.

The boiler 20 includes a iire box 2i, a combustion chamber 22, water spaces 23 surrounding the re box and combustion chamber, a water leg 24 terminating in a crown sheet 25 and a smoke pipe outlet 2B. The oil burner (not shown) is placed in the fire box and is accessible and supplied with fuel through the inlet 2l. The combustion gases normally flow from the combustion chamber 22, around the end of the crown sheet 25 through flues 28 and 29 to the smoke pipe outlet 26.

The fire box illustrated is made of refractory bricks in the usual manner and is provided with legs Si) by which it is supported upon the bottom of the boiler. Thus there is provided below the fire box a horizontal flue 3l connected by a passage 32 through the water leg 24 to the flue 29 opposite the smoke pipe outlet 26. It will be noted that the ue 3l is in contact with the water space at the bottom of the boiler as well as with the water leg 2d. A fire box made of metal may be substituted therefor if desired.

In the outer wall of the fire box are formed a plurality of vertical grooves 35 extending from top to bottom of the fire box and providing passages connecting the combustion chamber 22 with the fiue 3|. Under normal burning conditions the draft will cause the majority of the gases t0 rise through the chamber 22 and escape through the flues 23 and 29 but a certain fraction of the gases will descend through the passages provided by the grooves 35. When, however, due, for example, to pulsations, the pressures in the lire box arise suddenly, such pressures overcome the normal draft and cause allor arelatively larger portion of the gases to travel down the passages 35 to the flue 3i and thence through the passage 32 to the flue 29 and the outlet 26.

The gases thus escaping give up their heat to those portions of the boiler surface Which have heretofore been shielded and inaccessible to hot flue gases such as the water space below the flue 3| and the water leg 24.

Fig. 3 illustrates another form of fire box liti which difers from that previously described in the type of escape passages provided. The re box 40 here shown is particularly adapted for use in a boiler of the form shown in the copending Hannum, Seeley and Desjardins application Serial No. 306,280, led November 27, 1939. In the outer Wall of the fire box 40 are :formed vertical grooves 4I which function in the same manner as the grooves 35 to allow the escape of the excess gases. In place of grooves in the fire box, as shown in Figs, 2 and 3, there may be provided grooves 45 in the inner Wall of the boiler, as shown in Fig. 4.

The essence of this invention is the provision of passageways through Which excess gases may escape to the Hue, and while three embodiments of this invention have been shown and described, the invention is not limited thereto and other embodiments may be made Without departing from the spirit and scope of the invention as set forth in the following claims.

I claim:

1. In a boiler having a smoke pipe, a fire box, a combustion chamber above said fire box, and flues connecting said combustion chamber with said smoke pipe and through which gases normally travel, said re box having grooves, in the outer wall thereof, which grooves extend :from top to bottom of the lirebox and provide passages through which gases may also flow, and a ilue below said fire box and connected with said smoke pipe into which said gases are guided by said passages.

2. In a boiler having a smoke pipe, a re box, a combustion chamber above said fire box, said smoke pipe being located at a level below said combustion chamber, lues connecting said combustion chamber with said smoke pipe and through which gases travel, water spaces surrounding the re box, grooves extending from top to bottom of the fire box between said re box and said Water spaces and forming passages, and a iiue below said fire box into which gases flowing through said passages enter, said flue being connected to said smoke pipe.

LAUREN E. SEELEY. 

